package com.yupi.picturebackend.service.impl;

import cn.hutool.core.util.NumberUtil;
import cn.hutool.core.util.ObjUtil;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.yupi.picturebackend.exception.BusinessException;
import com.yupi.picturebackend.exception.ErrorCode;
import com.yupi.picturebackend.exception.ThrowUtils;
import com.yupi.picturebackend.mapper.SpaceMapper;
import com.yupi.picturebackend.model.dto.space.analyze.*;
import com.yupi.picturebackend.model.entity.Picture;
import com.yupi.picturebackend.model.entity.Space;
import com.yupi.picturebackend.model.entity.User;
import com.yupi.picturebackend.model.vo.space.analyze.*;
import com.yupi.picturebackend.service.PictureService;
import com.yupi.picturebackend.service.SpaceAnalyzeService;
import com.yupi.picturebackend.service.SpaceService;
import com.yupi.picturebackend.service.UserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
@Slf4j
@Service
public class SpaceAnalyzeServiceImpl extends ServiceImpl<SpaceMapper, Space>
        implements SpaceAnalyzeService {

    @Resource
    private UserService userService;

    @Resource
    private SpaceService spaceService;

    @Resource
    private PictureService pictureService;

    @Override
    public List<Space> getSpaceRankAnalyze(SpaceRankAnalyzeRequest spaceRankAnalyzeRequest, User loginUser) {
        ThrowUtils.throwIf(spaceRankAnalyzeRequest == null, ErrorCode.PARAMS_ERROR);

    // 仅管理员可查看空间排行
        ThrowUtils.throwIf(!userService.isAdmin(loginUser), ErrorCode.NO_AUTH_ERROR, "无权查看空间排行");

    // 构造查询条件
        QueryWrapper<Space> queryWrapper = new QueryWrapper<>();
        queryWrapper.select("id", "spaceName", "userId", "totalSize")
                .orderByDesc("totalSize")
                .last("LIMIT " + spaceRankAnalyzeRequest.getTopN()); // 取前 N 名

    // 查询结果
        return spaceService.list(queryWrapper);
}

    @Override
    public List<SpaceUserAnalyzeResponse> getSpaceUserAnalyze(SpaceUserAnalyzeRequest spaceUserAnalyzeRequest, User loginUser) {
        ThrowUtils.throwIf(spaceUserAnalyzeRequest == null, ErrorCode.PARAMS_ERROR);
        // 检查权限
        checkSpaceAnalyzeAuth(spaceUserAnalyzeRequest, loginUser);

        // 构造查询条件
        QueryWrapper<Picture> queryWrapper = new QueryWrapper<>();
        Long userId = spaceUserAnalyzeRequest.getUserId();
        //补充用户id查询
        queryWrapper.eq(ObjUtil.isNotNull(userId), "userId", userId);
        fillAnalyzeQueryWrapper(spaceUserAnalyzeRequest, queryWrapper);

        // 分析维度：每日、每周、每月
        String timeDimension = spaceUserAnalyzeRequest.getTimeDimension();
        switch (timeDimension) {
            case "day":
                queryWrapper.select("DATE_FORMAT(createTime, '%Y-%m-%d') AS period", "COUNT(*) AS count");
                break;
            case "week":
                queryWrapper.select("YEARWEEK(createTime) AS period", "COUNT(*) AS count");
                break;
            case "month":
                queryWrapper.select("DATE_FORMAT(createTime, '%Y-%m') AS period", "COUNT(*) AS count");
                break;
            default:
                throw new BusinessException(ErrorCode.PARAMS_ERROR, "不支持的时间维度");
        }

        // 分组和排序
        queryWrapper.groupBy("period").orderByAsc("period");

        // 查询结果并转换
        List<Map<String, Object>> queryResult = pictureService.getBaseMapper().selectMaps(queryWrapper);
        return queryResult.stream()
                .map(result -> {
                    String period = result.get("period").toString();
                    Long count = ((Number) result.get("count")).longValue();
                    return new SpaceUserAnalyzeResponse(period, count);
                })
                .collect(Collectors.toList());
    }


    @Override
    public List<SpaceSizeAnalyzeResponse> getSpaceSizeAnalyze(SpaceSizeAnalyzeRequest spaceSizeAnalyzeRequest, User loginUser) {
        ThrowUtils.throwIf(spaceSizeAnalyzeRequest == null, ErrorCode.PARAMS_ERROR);

        // 检查权限
        checkSpaceAnalyzeAuth(spaceSizeAnalyzeRequest, loginUser);

        // 构造查询条件
        QueryWrapper<Picture> queryWrapper = new QueryWrapper<>();
        fillAnalyzeQueryWrapper(spaceSizeAnalyzeRequest, queryWrapper);

        // 查询所有符合条件的图片大小
        queryWrapper.select("picSize");
        List<Long> picSizesList = pictureService.getBaseMapper().selectObjs(queryWrapper)
                .stream()
                .map(size -> ((Number) size).longValue())
                .collect(Collectors.toList());

        // 定义分段范围，注意使用有序 Map
        Map<String, Long> sizeRanges = new LinkedHashMap<>();
        sizeRanges.put("<100KB", picSizesList.stream().filter(size -> size < 100 * 1024).count());
        sizeRanges.put("100KB-500KB", picSizesList.stream().filter(size -> size >= 100 * 1024 && size < 500 * 1024).count());
        sizeRanges.put("500KB-1MB", picSizesList.stream().filter(size -> size >= 500 * 1024 && size < 1 * 1024 * 1024).count());
        sizeRanges.put(">1MB", picSizesList.stream().filter(size -> size >= 1 * 1024 * 1024).count());

        // 转换为响应对象
        return sizeRanges.entrySet().stream()
                .map(entry -> new SpaceSizeAnalyzeResponse(entry.getKey(), entry.getValue()))
                .collect(Collectors.toList());
    }



    @Override
    public List<SpaceTagAnalyzeResponse> getSpaceTagAnalyze(SpaceTagAnalyzeRequest spaceTagAnalyzeRequest, User loginUser) {
        ThrowUtils.throwIf(spaceTagAnalyzeRequest==null,ErrorCode.PARAMS_ERROR);
        //检查权限
        checkSpaceAnalyzeAuth(spaceTagAnalyzeRequest, loginUser);

        //构造查询条件
        QueryWrapper<Picture> queryWrapper = new QueryWrapper<>();
        fillAnalyzeQueryWrapper(spaceTagAnalyzeRequest,queryWrapper);

        //查询所有符合条件的标签
        queryWrapper.select("tags");
        List<String> tagsJsonList =  pictureService.getBaseMapper().selectObjs(queryWrapper)
                .stream()
                .filter(ObjUtil::isNotNull)
                .map(Object::toString)
                .collect(Collectors.toList());

        //解析标签并统计
        Map<String, Long> tagCountMap = tagsJsonList.stream()
                //["java","php"],["java","python"]=>"java","php"，"java","python"
                .flatMap(tagsJson -> JSONUtil.toList(tagsJson, String.class).stream())
                .collect(Collectors.groupingBy(tag -> tag, Collectors.counting()));

        //转化为响应对象，按照使用次数进行排序
        return tagCountMap.entrySet().stream()
                .sorted((e1,e2)->Long.compare(e2.getValue(), e1.getValue()))//降序排序
                .map(entry->new SpaceTagAnalyzeResponse(entry.getKey(),entry.getValue()))
                .collect(Collectors.toList());
    }
    @Override
    public SpaceUsageAnalyzeResponse getSpaceUsageAnalyze(SpaceUsageAnalyzeRequest spaceUsageAnalyzeRequest, User loginUser) {
        //校验参数
        //全空间或公共图库，需要从Picture 表查询
        if(spaceUsageAnalyzeRequest.isQueryAll()||spaceUsageAnalyzeRequest.isQueryPublic()){
             //权限校验
            //仅管理员可以访问
            checkSpaceAnalyzeAuth(spaceUsageAnalyzeRequest, loginUser);
            //统计公共图库的使用空间
            QueryWrapper<Picture> queryWrapper = new QueryWrapper<>();
            queryWrapper.select("picSize");
            //补充查询范围
            fillAnalyzeQueryWrapper(spaceUsageAnalyzeRequest,queryWrapper);
            List<Object> pictureObjList = pictureService.getBaseMapper().selectObjs(queryWrapper);
            long userSize=pictureObjList.stream().mapToLong(obj->(Long)obj).sum();
            long userCount=pictureObjList.size();
            //封装返回结果
            SpaceUsageAnalyzeResponse spaceUsageAnalyzeResponse = new SpaceUsageAnalyzeResponse();
            spaceUsageAnalyzeResponse.setUsedSize(userSize);
            spaceUsageAnalyzeResponse.setUsedCount(userCount);
            //公共图库（或者全部空间）无数量和容量限制，也没有比例
            spaceUsageAnalyzeResponse.setMaxSize(null);
            spaceUsageAnalyzeResponse.setSizeUsageRatio(null);
            spaceUsageAnalyzeResponse.setMaxCount(null);
            spaceUsageAnalyzeResponse.setCountUsageRatio(null);
            return spaceUsageAnalyzeResponse;
        }else {
            //特定空间可以从Space表查询
            Long spaceId = spaceUsageAnalyzeRequest.getSpaceId();
            ThrowUtils.throwIf(spaceId==null||spaceId<=0,ErrorCode.PARAMS_ERROR);
            //获取空间信息
            Space space = spaceService.getById(spaceId);
            ThrowUtils.throwIf(space==null,ErrorCode.NOT_FOUND_ERROR,"空间不存在");
            //校验权限
            checkSpaceAnalyzeAuth(spaceUsageAnalyzeRequest,loginUser);
            //封装返回结果
            SpaceUsageAnalyzeResponse spaceUsageAnalyzeResponse = new SpaceUsageAnalyzeResponse();
            spaceUsageAnalyzeResponse.setUsedSize(space.getTotalSize());
            spaceUsageAnalyzeResponse.setUsedCount(space.getTotalCount());
            spaceUsageAnalyzeResponse.setMaxSize(space.getMaxSize());
            spaceUsageAnalyzeResponse.setMaxCount(space.getMaxCount());
            //计算比例
            double sizeUsageRatio = NumberUtil.round(space.getTotalSize()*100.0/space.getMaxSize(),2).doubleValue();
            double countUsageRatio = NumberUtil.round(space.getTotalCount()*100.0/space.getMaxCount(),2).doubleValue();
            spaceUsageAnalyzeResponse.setSizeUsageRatio(sizeUsageRatio);
            spaceUsageAnalyzeResponse.setCountUsageRatio(countUsageRatio);
            return spaceUsageAnalyzeResponse;
        }
    }


    @Override
    public List<SpaceCategoryAnalyzeResponse> getSpaceCategoryAnalyze(SpaceCategoryAnalyzeRequest spaceCategoryAnalyzeRequest, User loginUser) {
        ThrowUtils.throwIf(spaceCategoryAnalyzeRequest==null,ErrorCode.PARAMS_ERROR);
        //检查权限
        checkSpaceAnalyzeAuth(spaceCategoryAnalyzeRequest, loginUser);

        //构造查询条件
        QueryWrapper<Picture> queryWrapper = new QueryWrapper<>();
        fillAnalyzeQueryWrapper(spaceCategoryAnalyzeRequest,queryWrapper);

        //使用mybatisplus
        queryWrapper.select("category","count(*) as count","sum(picSize) as totalSize")
                .groupBy("category");

        //查询并转换结果
        return pictureService.getBaseMapper().selectMaps(queryWrapper)
                .stream()
                .map(result -> {
                    String category = (String) result.get("category");
                    Long count = ((Number) result.get("count")).longValue();
                    Long totalSize = ((Number) result.get("totalSize")).longValue();
                    return new SpaceCategoryAnalyzeResponse(category, count, totalSize);
                })
                .collect(Collectors.toList());
    }

    /**
     * 校验空间分析权限
     * @param spaceAnalyzeRequest
     * @param loginUser
     */
    private  void checkSpaceAnalyzeAuth(SpaceAnalyzeRequest spaceAnalyzeRequest, User loginUser) {
        boolean queryPublic = spaceAnalyzeRequest.isQueryPublic();
        boolean queryAll = spaceAnalyzeRequest.isQueryAll();
        //全空间分析或者公共图库权限校验，进管理员可访问
        if (queryAll||queryPublic) {
            ThrowUtils.throwIf(!userService.isAdmin(loginUser), ErrorCode.NO_AUTH_ERROR);
        }else {
            //分析特定空间，仅本人或者管理员可以访问
            Long spaceId = spaceAnalyzeRequest.getSpaceId();
            ThrowUtils.throwIf(spaceId==null, ErrorCode.PARAMS_ERROR);
            Space space = spaceService.getById(spaceId);
            ThrowUtils.throwIf(space==null, ErrorCode.NOT_FOUND_ERROR,"空间不存在");
            spaceService.checkSpaceAuth(loginUser,space);

        }
    }

    /**
     * 根据请求对象封装查询条件
     * @param spaceAnalyzeRequest
     * @param queryWrapper
     */
    private void fillAnalyzeQueryWrapper(SpaceAnalyzeRequest spaceAnalyzeRequest, QueryWrapper<Picture> queryWrapper) {
        boolean queryAll = spaceAnalyzeRequest.isQueryAll();
        //全空间分析
        if (queryAll){
            return;
        }
        boolean queryPublic = spaceAnalyzeRequest.isQueryPublic();
        //公共图库
        if (queryPublic){
            queryWrapper.isNull("spaceId");
            return;
        }
        //分析特定空间
        Long spaceId = spaceAnalyzeRequest.getSpaceId();
        if(spaceId!=null){
            queryWrapper.eq("spaceId", spaceId);
            return;
        }
        throw  new BusinessException(ErrorCode.PARAMS_ERROR,"未指定查询范围");

    }



}
